Grinding machine



Aug. 20, 1935. F. s. HAAS ET AL v GRINDING MACHINE l0 Sheets-Sheet 1Filed May 31, 1930 7 d y w a. Z Z; I ,4.

. Aug. 20, 1935. I F. s. HAAS ETAL 2,012,065

GRINDING MACHINE Filed May 31, 1930 10 Sheets-heet 2 g Q w gm Denice; v

1935. R5. HAAS El AL 2,012,065

' GRINDING MACHINE Filed May 31, 1950 10 Sheets-Sheet 3 Zlwueniozilllilllllmmlllllllllllllllllll'l un 'im m WMW' Aug. 20, 1935. F. s. HAAsAL GRINDING MACHINE 10 Sheets- Sheet 4 Filed May 31, 1950 Aug. 20, 1935.5, s ETAL 2,012,065

GRINDING MACHINE Filed May 31, 1930 l0 Sheets-Sheet 5 V z m JWntozJduommq Aug. 20, 1935. F. s. HAAS |-.-r AL GRINDING MACHINE Filed May 31,19so 1o Sheets-Sheet e Ill: 21/

, 2 w a W w Aug. 20, 1935. F s, AAs r AL 2,012,065

GRINDING momma Filed May 31, 1950 10 Sheets-Sheet 7 Aug. 20, 1935. F. s.HAAS ETAL 2,012,065

GRINDING MACHINE Filed May 31, 1950 l0 Sheets-Sheet 8 Wllfillllllllllllllll II ll ll Hlll I I I I I I I I I I I I I I I I I I II I Aug. 20, 1935.

F. s. HAAS ET AL 2,012,065

GRI-NDING MACHINE Filed May 31, 1930 10 Sheets-Sheet 9 Swuantoz;

Aug. 20, 1935. 1F. 5. H A s AL GRINDING MACHINE Filed May 31 1950 10sneaks-sheet 1o IVII/lIIIIIIIIIIIIIl/lflll/I/ I I 1 I n Patented Aug.20, 1935 GRINDING MACHINE Frederick S. Haas, Cincinnati, and Ralph .L.Goetzel, Norwood, Ohio, assignors to Cincinnati Grinders Incorporated,Cincinnati, Ohio, a corporation of Ohio Application May 31, 1939, SerialNo. 458,558

18 Claims.

This invention relates to improvements in grinding machines andespecially to improvements in such machines for operation on work piecesheld between centers.

In the performance of grinding operations on work pieces held betweencenters there are two methods generally employed, in the first methodthe work piece is held between the centers on the table or supportingmember which is then traversed across'the face of the grinding wheel toreduce the work piece throughout its length to the same size whilein-the second method the supporting member, centers and work piececarried thereby are held stationary asrespects this traversing movementand the grinding wheel fed into the work piece for effecting a stockremoval therefrom. In the former method of grinding the grinding wheelor tool is fed into the work piece at the end of each reciprocatingstroke until the work piece is reduced to the desired size and the tableis traversed between the increments of feeding.-

It is, therefore, one of the principal objects of the. present:;invention to provide a universal grinding machine that may besatisfactorily employed for performing either of the above men tionedmethods of grinding- Another object of the invention is the .provisionof improved means for actuating the several moveable members of theimproved grind! ing machine in the most expeditious manner to eliminateall unnecessary movements and increase the production of the machine tothe maximum.

Another object of the invention is the provision of improved means foreffecting the translation of the work supporting memberwhile performingthe grinding operation by traversing the work supportingtable and workacross the face of the grinding wheel together with improved means forfeeding the said grinding wheel or tool into the work at each end of thestroke of the table.

A further object ofthe invention 'isthe provision of improved means foractuating the grinding wheel or tool carriage relative to the bed andfeed the tool into the work while the said work is being held stationaryon its supporting table as respects the longitudinal movement thereof.

j .A' still further and specific object of the invention, is theprovision of an improved grinding machine capable of performinguniversal grinding operations having the control and adjusting membersvwithin convenient reach of the operator sa that the machine may beadjusted in a minimum of time and with the least inconvenience for theperforming of the several methods of grinding.

Other objects and advantages of the present In the drawings:

Figure l is a front elevational view of a grinding machine embodying theimprovements of this invention.

Figure 2 is an elevational view of the machine as seen from the righthand side thereof in Figure 1.

Figure 3 is a transverse sectional view taken on line 3--3 of Figure 1.

Figure 4 is a fragmentary sectional view taken on line 4-4 of Figure 1.

Figure 5 is a view of several parts shown in Figure 4, as seen from line5-5 thereon.

Figure 6 is a sectional view taken on line 6-6 of Figure 4.

v Figure '7 is a sectional view taken on line 'I-l of Figure 6.

Figure 8 is a developed view showing the several positions of theactuating parts which effect the reciprocation of the work table as seensubstantially from line 8 8 of Figure 1.- Figure 9 is a sectional viewtaken on line 9-9 of Figure 8.

Figure 10 is a sectional view taken on line HI- ID of Figure 8.

Figure 11 is a sectional view through the man- 'ual tool slide feedingmeans as seen from lineli-|l of Figure 1.

Figure 12 is a sectional view taken on line l2- l2 of Figure 1.

Figure 13 is a sectional view as seen fromline l3-'l3 of Figure 3.

Figure 14 is a sectional view taken on' line l4-l4 of Figure 3.

Figure 15 is a sectional view as seen from line I [5-45 of Figure 1.

Figure 16 is a sectional view taken on line I6l6 of Figure 11.

Figure 1'1 is a sectional view taken on line l'|-,-l1' of Figure 3showing certain details of the operating structure.

Figure 18 is a view taken on line l8-l8 of Figure 1 showing the sizecontrol mechanism in elevation in operative engagement with the workpiece.

Figure 19 is a view similar to Figure 18 showing the size controllingmechanism in an inoperative position.

Figure 20 is a longitudinal sectional view through the size controllingmechanism illustrating the internal mechanism thereof.

Figure 21 is a diagrammatic view illustrating the hydraulic and electriccircuits involved in the control of the several moveable parts of thisinvention.

Figure 22 is a fragmentary sectional view taken on line 2222 of Figure14.

Throughout the several views of the drawings similar referencecharacters are employed to denote the same or similar parts.

In general the improved grinding machine of this invention issemi-automatic in performanceand includes hydraulic and electric meansfor controlling the various movements of the machine. The machineincludes the usual bed or support having mounted thereon a worksupporting table reciprocable longitudinally of the length of the bed orsupport. Improved novel means for controlling and effecting the saidreciprocation of the table are employed. In addition a tool slideoperable transversely of the bed or support is controlled by improvednovel electric and hydraulic means. The hydraulic and electric means foreffecting the reciprocation of the table are interlocked with themovement of the tool slide toward and from the said table through animproved work piece size mechanism. The several movements of the tableand tool slide are also under control of suitable handles or leverswithin convenient reach of the operator from his normal working positionat the forward end of the machine. All of the foregoing mechanisms areclearly illustrated in the drawings and will be described in detaillater.

Referring to the drawings and specifically to Figures 1, 2 and 3 thereis disclosed is. bed or support 25 having formed longitudinally thereofat its forward end ways 26 and 21 for guiding during its reciprocatingmovement a work supporting table 28. Adjustably carried by the table atopposite ends thereof is the headstock 29 and tailstock 38 from whichcenters 3| and 32 respectively project. The centers 3| and 32 support awork piece 33 between them. The headstock 29 has a motor or prime-mover34 connected through suitable transmission means enclosed within casing35 with the spindle which carries the live center 3|. To effect rotationof the work piece 33 from the spindle or center 3| a dog 36 is securedto the work piece and bridged over by driving pin 31 to the saidspindle. The work piece 33 is removed from between the centers 3| and 32by retracting the said center 32 through the medium or handle 38 carriedby the tailstock 30.

The table 28 and work 33 are reciprocated longitudinally of the bedwhile effecting a stock removal from the surface of the work throughoutits length by a suitable tool or grinding wheel 39- supported by the bedfor this purpose. To effect the said movement of the table 28 use ismade of an hydraulic motor 40 disclosed in Figures 8 and 9. The motor 49is rotated by an hydraulic medium in an hydraulic circuit which will beexplained in detail later. The said motor 40 comprises gears 4| and 42secured respectively toback gear shaft 43 and stub shaft 44. The stubshaft 44 is formed on its inner end with an enlarged head 45 havingclutch teeth 46 for engagement with similar clutch teeth 41 on driv inggear 48. The driving gear 48 is keyed or splined to driving shaft 49 andthe said gear is, slidable relative to the said shaft 49 but rotatabletherewith. The driving shaft 49 is journaled in anti-friction bearingsmounted in the walls of gear box or bracket member 58 and has securedthereto or formed integral therewith intermediate to said anti-frictionbearings a worm 5|. The worm 5| meshes with and drives a worm wheel 52keyed or otherwise secured to vertical pinion shaft 53. This shaft 53 isjournaled in anti-friction bearings carried by the bracket or housingand is connected by cap screws or the like 54 with a driving coupling55. The driving coupling 55 is provided with a flange 56 through whichthe said cap screws 54 extend into a collar or flange 51 formed on theupper end of shaft 53 and the coupling 55 is splined to a pinion shaft58 co-axial with the shaft 53. The pinion shaft 58 has integraltherewith a pinion 59 having its teeth in mesh with the teeth of a rack68 secured to the under surface of the table 28.

From the foregoing it will be noted that if gear 48 were shifted toengage its clutch teeth 41 with the clutch teeth 43 a direct drivingconnection between the hydraulic motor 49 and table 28 would beestablished to actuate the said table at its maximum rate. To effect theshifting of the gear 48 it is provided with a circumferential groove 6|receiving shifter pin 62 carried by one end of bell crank 63 pivoted at64 to the bracket or housing 50. The other end of the bell crank 63 isbifurcated to provide arms 65 and 66 receiving therebetween a pin 61extending from a link 68. The link 68 is pinned or otherwise secured toa shaft 69 journaled in a sleeve 10 carried by the bracket 50. Securedto the outer end ,of the shaft 69 exterior of the housing 59 and withinconvenient reach of an operator is a {handle 1| whereby the shaft 69 maybe rocked.

The handle 1| has four positions, the first of which is the shifting ofthe gear 48 to engage the clutch teeth 41 and 46 for effecting arotation of pinion shaft 58 and pinion 59 and actuate the table at itsmaximum speed. The second position of the handle shifts the gear 48 tothe position shown in Figure 8 at which time the clutch teeth 46 and 41are out of engagement, and the gear 48 is in a neutral position toeffect a complete stopping or non-movement of the said table 28.Continued movement of the handle H in a clockwise direction to its thirdposition would mesh the teeth of the gear 48 with the teeth of a gear I2pinned or otherwise secured to a shaft 13 journaled in anti-frictionbearings carried by the walls of the bracket or housing 50. In thisposition the worm shaft 49 is rotated by manual means such as the handwheel 14 mounted on the forward face of the bed or support 25. Thisrotation of the shaft 13 is effected through a pair of bevel gears 15and 16, the former being keyed or otherwise secured on the shafts 13,while the latter is pinned to a stud l1 journaled in the walls of thebracket or housing 50. Similarly pinned to the outer end of the stud I1is a pinion 18 in mesh with a gear 19 secured by cap screws or the like80 to the'hand wheel 14, the hand wheel 14 and gear 19 being mounted forrotation about a stud 8| carried by the bracket 58. The fourth or lastposition of the handle or lever II meshes the teeth of the gear 48 witha pinion 82 integral with or secured .to the shaft 43 of motor gear 4|of hydraulic motor 40 to effect the rotation of worm shaft 49 at aslower rate from the said hydraulic motor 40.

From this it will be seen that thtable 28 may be longitudinally actuatedat differential speeds under power or the said table may be manuallyreciprocated. 7

As was noted above the motor 40 has the gears thereof rotated by anhydraulic medium under pressure. This hydraulic medium is normallycontained within a tank 83 from which it is drawn through a conduit 84by a pump 85 and discharged from the pump under pressure through aconduit 88. The medium then passes through a conduit 81 to starting andstopping valve 88 from which it passes through port 89 formed along theexterior valve sleeve 90 to a port 9| for direction. to the interior ofthe sleeve 90 passing then through port 92 to conduit 93 for conveyanceto the directional control or reverse valve 94 which directs the mediumto one side or the other of hydraulic motor 40. As shown in Figure 21,the medium passes through the conduit 95 from the valve 94 to the lowerside of motor I 40. The spent medium discharged on the other side of themotor is directed through a conduit 99 back to the valve 94 fordischarge through a conduit 91 to the sump or tank 83. The valve 88 inaddition'to being used as a starting and stopping'valve controls thevelocity' or rate at which the table 28 is being reciprocated and is ofa unique, novel construction. This valve comprises a pair of spools 88aand 88b, each having.

a bore therein in axial alignment 1;? receive a spring 98 which tends toactuate the spools in opposite directions. The cannelure formed in spool88b is utilized for connecting ports 9| and 92 formed in the sleeve 90while the cannelure of spool 88a connects a pair of similar ports 99 andI00 formed in the said sleeve 90. The velocity or rate of movement ofthe table by the hydraulic motor is controlled more or less by closingoff the port 99 by the shoulder IOI formed by the cannelure in' valvespool 88a.

As was noted above, the spring 98 tends to actuate the spools 88a and88b in opposite directions or away from one another and thereby holdsthe said spools in engagement with adjustable stops I02 and I03respectively, carried by a. pivotally mounted bell 'crank I04 and by anarm I05. The crank I04 is pivotally mounted at I06 to the bracket 'orhousing 50 and has a second arm I01 extending therefrom The arm I01 ofbell crank I04 is provided with a nose I08 contacting at all times withcam face I09 formed ona flange of sleeve III! journaled for rotationabout a sleeve III. Secured to the outer end of the sleeve 0 is a handleI I2 having a spring pressed locking pawl cooperating with a serrated ortoothed plate II3 secured to the cover of the bracket or housing50-positioned on the forward face of the bed 25 within convenientelectrically connected. From this it will be noted reach of theoperator. Adjustment of the handle II2 rotates the sleeve II!) foradjusting the position of cam I09 to thereby shift the spool 88a andvary the opening of port I00 to control the flow of the hydraulic mediumtherethrough, As

shown in Figure 6, the port I00 is partly open to permit a normalshifting of the table so that the removal of stock from the work piece33.

takes place at the desired-rate. I

While the flow of the medium through the port I00 is restricted duringactualoperation of the machine, the flow from the port 89 formedlongitudinally of the sleeve 90 is shut off by the spool valve 88b tostop the reciprocation of the table but an unrestricted fiow ispermitted during actual operation. Asishown in Figure 6, ports 9I and 92are connected permitting, as noted above, an unrestricted flow of themedium therethrough. This spool 88b is shifted by the arm I95 pivotedabout pivot II4 carried by the rear wall of the bracket or housing 50.The upper end of arm I08 is pivotally connected to a longitudinallyshiftable link I I5 which has its opposite end pivotally connected tosmaller crank arm IIS pivotally carried by pivot I96. The other arm II1of bell crank H6 is provided with a cam follower H8 at all times held inengagement with the stepped cam I I 9 formed on a flange I20 carried bythe sleeve III; Pivotally secured to the outer endof the sleeve III isthe main starting and stopping lever I2I which may be rocked in aclockwisedirection to shift the valve spool 88b and open port 9| topermit the table 28 to be actuated at a normal work feeding rate. Fromthe foregoing it will be noted that handle II2 may be adjusted forpositioning valve spool 88a to determine the rate of speed at which thework supporting table will be reciprocated. It will also be noted thatwith starting and stopping lever in its neutral or central position theflow of the hydraulic medium is restricted to stop the movement of thetable while a shifting thereof to the right or in a clockwise directionwill open port 9I and permit a flow ofthe medium there throughdetermined by the setting of the valve spool 88a.

There are times when it is desirable to reciprocate the work table 28 ata high or rapid traverse rate, such as when grinding bearing portions atopposite ends of a shaft, for example, to thereby materially reduce thetime involved in completing a given grinding operation. To this end thearm I01 of bell crank I04 is provided with a pin I22 in the path ofmovement of an abutment I23,

shown in Figure 4 as an adjustable screw, carried by a projection onflange I20 of sleeve III. Rotation of main starting and stopping leverI2I in a counter clockwise I00 and perspending speeding up of rotationof the pump gears to correspondingly rapidly rotate the pinion shaft 58and reciprocate the table at a rapid rate.

The longitudinally shiftable bar I I5 has secured thereto a projectionI24 abutting on opposite sides with adjacent ends of springs I25 and I29through which depressible plungers I21 and I28 of stopping and startingswitches I29 and I30 fare actuated to stop and start the headstockrotating motor 34 with which the said switches. are

that actuation of the lever I2I to effect reciproe cation of the table28 simultaneously effects the rotation of the motor 34 and work piece 33rotated thereby.

The directional control or reversing valve 94 is shifted at each end ofthe stroke of the table 28 to thereby reverse the movement of the table,To

this end the valve 94 is provided witha-shifter'.

rod I3I having a forked end and receiving be- I32 into an elongatedperforation I36 formed in the upper end of one arm of bell crank I31.This bell crank I31 is pivoted at I38 and has its other arm I39 pivotedat I40 with one end of a link I4I. Carried by the bell crank I31 andprojecting into the perforation I36 therein and from opposite sidesthereof is a pair of set screws I42 and I43 adapted to engage with thepin I35 of lever I32.

The upper end of the link MI is pivotally connected to a crank arm I44integral with a sleeve I45 journaled about a hollow shaft I46 supportedby the bracket or housing 50. Keyed or otherwise secured to the outerend of sleeve I45 is a reversing lever I41 extending upwardly above thebed 25 and having a projection I48 extending therefrom toward the saidbed 25. The table 28 has secured to its forward edge on opposite endsthereof dogs I49 and I50 adapted to engage the projection I46 foroscillating same about its axial center or hollow shaft I46.

At each end of the stroke of the table a slight pause is effectedfollowed by a gradual increase in speed of movement of the table in theopposite direction. This pause iseffected by an hydraulic tarry valveenclosed within the casing I34. Vertically shiftable through the casingI34 is a pair of spool valves II and I52 having co-axial bores thereinfor a spring I53. The spool valve I5I is enclosed within a sleeve I54through which ports I55 and I56 are formed. A cannelure I51 formed inthe spool valve I5I connects the ports I55 and I56. The spool valve I52is likewise enclosed in a sleeve I58 having ports I59 and I60 connectedtogether by the passage I6I formed on the spool I52. The hydraulicmedium under pressure is conveyed to the casing I34 through a conduitI62 coupled into the casing containing the reversing valve 94 and is indirect communication with the main pressure line 81. The spool valve I52 is provided with a reduced portion I63 having formed at the endthereof a wedge shape head I64 having cam faces on opposite sidesthereof. These cam faces cooperate with similar cam faces formed on theend of valve shifter lever I32. A pin I65 projects from the valve spoolhead I64 to which is attached one end of a spring I66 the other end ofwhich spring is secured to a pin I61 projecting from the rear face ofbell crank I31. Referring to Figure '7, it will be noted that port I55of sleeve I54 is connected with port I60 of sleeve I 58 by alongitudinal port I68. Thechamber I69 formed between valve spools I 5|and I52 and their containing sleeves I54 and I58 is drained through aport I formed in the valve casing I34.

Assuming the table to be traveling to the left as seen in Figure 1, thedog I50, upon engagement with the projection I48 would rotate lever I41and sleeve I45 which through the. crank I44 would depress link I4I. Thisdepression of link I4I actuates the bell crank I31 in a counterclockwise direction to take up the lost motion between the pin I35 andabutment set screw I42 and at the same time through the interengagementof the contacting cam faces on the upper end of the bell crank with thecam face on head I64 forces upwardly the said head I64 and spool valveI52 permitting the hydraulic medium flowing through the conduit I62 tofill the passage I6I. By oscillating the bell crank I31 until the lostmotion between the ends of set screws I42 and I43 is taken up the apexof the cam faces on the bell crank I31 is beyond the point of head I64.At this time the spring I66 which was tensioned by the raising of thehead I64 tends to actuate the said head downwardly thereby bringing intoengagement the opposite cam faces. This downward movement of the headand valve spool while freely moved upward is now restricted in itsdescent since it must force outwardly from the passage I6I the hydraulicmedium therein. The medium is discharged through port I60 to port I68tothe upper port I55 in sleeve I54. The flow of the medium through theport I55 is restricted by the shoulder on the valve I5I so that thedescent of the head I64 and valve spool I52 is restricted and theshifting of the valve 94 takes place only at the rate of movement of thehead. This movement gradually uncovers the port through which thehydraulic medium is passing to the hydraulic motor thereby slowlypicking up speed to correspondingly slowly accelerate the speed ofmovement of the table 28.

The adjustment of spool valve I5I is obtained through cam face I1Iformed on flange I12 of a sleeve I13 mounted for rotary movement aboutthe sleeve I45. A cam follower I14 projects from the spool valve I5I inengagement with the cam I H being held in this engagement by the' springI53. The sleeve I13 is adjusted by a handle I keyed or otherwise securedthereto andlocked in position by the interengagement of a spring pressedpawl I16 cooperating with a serrated or toothed plate I11. From this itWill be seen that the amount of tarry and rate of acceleration ofmovement of the table 28 after reversal may be adjusted to any desiredlimit.

The bed 25 has securedthereto behind the table 28 a plate or support I80having formed thereon ways I8I and I82 extending transversely of the bedfor guiding a tool carriage I83 for movement toward and from the table26 and work carried thereby. J ournaled in the tool carriage I83 is aspindle I84 supporting for rotation therewith a grinding wheel 39. Thegrinding Wheel is substantially enclosed with a guard or housing I86carried by the carriage I83 and moveable therewith. Depending from thecarriage I83 and secured thereto by cap screws or the like I81 is abracket I88 for a cylinder I89. Within the cylinder for movementrelative thereto is a piston I90 having extending from opposite sidesthereof hollow piston rods I9I and I92. The outer end I 93 of the pistonrod I92 is provided with internal threads meshing with the threads ofadjusting screw I94 journaled for rotative but not translative movementin the forward end I95 of intermediate plate or bracket I80. Keyed orotherwise secured to the screw I94 is a large gear I96 meshing with apinion 214 keyed to rotate with a trigger or trip shaft 215 to be laterdescribed in detail. A relatively large gear 350 is keyed for rotationwith the trigger or trip shaft 215 near its forward end and meshes .witha pinion I91 ,pinned or otherwise secured to one end of pinion shaftI98. A second pinion I99 is keyed to the shaft I98 near its other endand meshes with a similar pinion 200 on the end of shaft I rotatablethrough handle 202 carried by crank 203. A hand wheel 204 is journaledwithin a central boss of the crank 203 and keyed to the shaft 20I formovement therewith and has a driving connection with and relative to thecrank 203 through a pinion 205 carried by the said crank 203. The teethof the pinion 205 mesh with similar internal teeth 206 of an internalgear carried by the hand wheel 204. The pinion 205 has integraltherewith a stud 201 journaled in a relatively small plate 208 pinned orotherwise secured in the crank 203 for movement therewith. To the outerend of the stud 201 is a spring pressedlocking pin 209 engage-' able ina plurality of holes formed around the plate 208.

From the foregoing it will be noted that by grasping handle 202 androtating the crank 203 movement will be imparted to the hand wheel 204which in turn rotates the pinion shaft 20I and through the transmissiongearing, above noted, rotation is imparted to the screw I94 foradjusting the tool carriage l83, cylinder I89, piston I90 and partsassociated therewith relative to the intermediate plate or support andrelative to the adjusting screw I34. It will also be noted that bywithdrawing the plunger 209 from the particular locking bore thenengaged and advancing same to a different locking bore the stud 201 andpinion 205 will be rotated. The rotation of the pinion 205 will throughthe interengagement of its teeth with teeth of internal gear 206additionally rotate the hand wheel 204 and pinion shaft 20I to furtheradjust the parts as above noted. The foregoing description deals withthe manual means for initially setting up the machine for operation on aplurality of similar work pieces and for further adjusting the machineto take up for wheel wear to insure successive work pieces being reducedto the same size.

In the normal operation of the machine the tool carriage I83 is advancedtoward and retracted from the work piece by an hydraulic medium underpressure. Means are provided for varyingthe rate of movement ofthecarriage at a fast or rapid rate in both directions and additionallyat a'slow rate in one direction. This slow movement of the carriage inthe one direction may be either continuous as when performing a grindingoperation by the plunge method or the said slow movement of the carriagemay occm' intermittently as at the opposite ends of movement of the worktable 28. Means are also provided for determining-whether the carriagewill be actuated for plunge cut grinding or for intermittent feedingmovement when operating on a cylindrical bar or shaft, for example.

In utilizing the power or hydraulic means for actuating the slide thehydraulic medium passes through aconduit 2I0 from the main pressureconduit 86 to ,a slide valve 2 from which it is directed to one sideorthe other of piston I90. As shown in Figure 21, the mediumpasses fromthe valve sleeve 2 I2 through a conduit 2 I3 to the left hand side ofthe piston I 90 for actuating the carriage I83 toward the worksupporting table. The valve 2 is initially shifted through its sleeve toinitiate a movement of the grinding wheel carriage by a manuallyshiftable lever 2I4 pinned or otherwise secured on the end of the shaft2 I5. The shaft 2 I 5 is journaled in the wall of a projection 2 I6 ofbracket orhousing member 2 I1. On the inner end of the shaft 2 I 5interiorly cf the projection 2I6 is a link 2I8 pivotally connected to asecondlink 2I9 having its other end pivotally connected to lever 220.The lever 220 is keyed to a hollow shaft 255 having an operableconnection through a pin 253 projecting from a flange 254 on the hollowshaft 255 and an oscillatable plate 250 with a solid shaft I journaledfor rotation within the said hollow shaft whereby said solid shaft isactuated. Depending from the solid shaft 25I is a short lever 222 havinga forked end 223 received between adjustable abutments 225 fixed on theend of valve shifter rod 225.

By actuating the lever 2I4 in a counter clockwise direction or towardthe operator the valve 2| l is shifted to the position shown in Figure21,

to permit the hydraulic medium to pass through conduit 2I3 and actuatethe grinding wheel carriage toward the work supporting table. Thismovement is at a rapid rate and the medium in the cylinder on the righthand side of piston I90 is being discharged through an unrestrictedcon-' duit 226 to the valve sleeve 2 I2 at which point the medium flowsthrough a conduit 221 to the tank or sump 83. The movement of thecarriage continues until the flow of the medium is inter-, rupted eitherby being completely out off or by being forced to pass through arestricted orifice.

As was noted above, the movement of the carriage either continues in adirect line-into the work at a relatively slow rateor it is fed towardthe work at the completion of each longitudinal stroke of the workcarrier. Considering first the continuous movement of the carriage in astraight line, as when performing a plunge cut grinding operation, thefollowing mechanism is employed.

Mounted on the forwardface of the bed 25 in the housing 2I1 are variousvalves and control members each having a knob or control elementpositioned on the outside face of the box or bracket 2 I1. Referring nowto Figure 1, the knob or control element in the upper left hand corner.indicated by the numeral 228- determines whether the carriage will beactuated toward the work feeding movement, and the knob 23I directlybeneath the knob 230 adjusts the amount of feed of the wheel toward thetable at the completion of each stroke of the reciprocating work table28.

The knob 229 is pinned to a shaft 232 which 7 shaft is in turn pinned at233 to a sleeve 234. The sleeve 234 has a sliding keyed connection as at235 with a stud 236 of a worm screw 231. The stud 236 is adapted to beslidablyv actuated through the interior of the sleeve 234 withoutbreaking the driving connection therebetweep. A spring 238 is interposedbetween the face, of the sleeve 233 and the end of the stud 236 tendingto actuate the stud toward the right, as seen in Figure 3. This movementof the stud is restricted however, by a worm nut 238 threaded on theworm screw 231 having shoulders 240 formed at its opposite endsreceiving therebetween the forked end 24 of lever 242. The leverispivotally'mounted on a shaft 243'and restrained against movement by aspring 244 having one end connected to the lower end of the lever 242and its other end secured to a lug 245 formed on the inner face of thebracket or housing 2 I1. A latch 246, see Figures 11'and 17, is securedto the shaft 243 having a ledge or step 241 thereon for a trigger 248.By actuating the knob or control member 220 in the proper direction theworm nut 239 may be actuated toward the front of the machine to therebyrotate the shaft 243 and actuate the trigger 248, as seen in Figure 11,in a counter clockwise di ection thereby shifting the ledge or seat 241of the latch 246 relative to the end of trigger 248 so that the saidtrigger and latch overlapone another a predetermined amount,

the function of which will be explained in detail later.

The latch :46 is pivotally mounted betweeh the forked end 249 of theoscillatable plate 256 pinned or otherwise secured to the end of theshaft 25I. A spring pressed plunger 252 is carried by the plate 250 andbears against the latch 246 tending to rotate same in a counterclockwise direction about its pivot, as seen in Figure 11, for

holding the rear edge of the said latch against the seat formed by theforked end 249 of the plate 250. The plate 250 is further formed withanctch 252a receiving the pin 253 projecting from the flange 254 of thehollow shaft 255 in which the shaft 25I is rotatably journaled as abovementioned. Shiftable through the plate 250 adjacent the upper endthereof is a pin 256 abutting on one end the trigger 248 at a point onthe other side of the pivot from the abutment of the plunger 252. Thepin 252 on its other end engagesthe driving pin 253. The other end ofthe hollow shaft 255 has secured to it the arm 228 while the same end ofthe shaft 2 5I carries the arm 222 connected with the valve stem 225 foractuating the valve 2| I. A spring 251 is secured to the arm 228 and toa lug 258 extending inwardly from the front wall of bracket or housing 2[1.

From the foregoing it will be noted thata push on the end of the wormscrew 231 will cause stud 236 to be telescoped within the sleeve 234carrying with it the worm nut 239 and through the shoulders or abutments249 thereon a movement of lever 242 and shaft 243 in a counter clockwisedirection. This rotation of shaft 243 moves the latch 246 away from-thetrigger 248 whereupon step 259 of plate 268 secured to the bracket 2".

At the same time the movement of the plate 250 rocks 'the shaft 25I andvalve shifter arm 222 connected thereto for shifting the valve 2 to theleft, as seen in Figure 21, connecting the discharge port 262 in sleeve2I2 through the cannelure 263 of valve 2H with the port 264 of a con-"duit 265. The conduit 285 extends to a valve chamber 266 controlled bythe knob 228.

As was noted above'the knob or control member 228 is adapted to beadjusted or set to effect a continuous movement of the tool carriage I83toward the work supporting tab 1e 28 or it may be set to permit anintermittent movement of the tool carriage toward the table, namely, ateach end of the stroke of the table. As shown diagrammatically in Figure21, the knob 228 is connected to a valve adjustable within the valvecasing 266 to direct the flow of the medium through either of two ports261 or. 268 formed therein; The setting of the valve here shown directsthe flow-of the medium through a conduit 269 to a needle valve casing210. This casing the work supporting table 28 untilthe grinding wheel 39is positioned a predetermined amount Shaft.

from the work piece, which is controlled by the setting .of the trigger248 relative to the ledge or seat 241 on latch 246, at which time therate of movement of the grinding wheel into the work will be materiallyreduced. This changing of the rate of movement of the wheel isautomatically effected by shifting the trigger from beneath the latch topermit a shifting of the valve 2 to the left to connect the dischargeconduit 226 from the cylinder I89 with the conduit 265 through which themedium is controlled on its way to the tank or sump 83. r

.; The mechanism for automatically shifting the valve 2 comprises abracket 213 in which is rotatably mounted the gear 214 slidably splinedfor rotative movement therewith but for axial movement relative to theshaft 215, which, for convenience has been termed a trigger or trip Theouter end of the trip shaft 215 has an abutment 216 seated against theend of worm screw 231 having a splined portion 211 adjacent theretoreceiving the driven gear of the hand adjustment transmission aboveindicated. Projecting from the other end of trip or trigger shaft 215 isa screw'218 threaded into a nut 219 fixed in a bracket 288 carried bythe intermediate plate I80. One end of the nut 219 is counter bored andprovided with internal threads receiving the external threads of asleeve nut 28 I The nut 28I has a flange 282 formed on its outer endadapted to abut a shifter fork 283 depending from the cylinder bracketI88. A look nut 284 is threadedly carried by the sleeve nut 28I to lockthe nut 219 and sleeve 28I in position relative one to the other so thatthe abutment flange 282 is fixed relative to the screw portion 218.

From this it will be seenthat as the tool carriage I83 is actuatedtoward the work table and work the shifter fork 283 carried thereby willengage with abutment flange 282 and shift the trip or trigger shaft 215forwardly to actuate the worm screw 231 and stud 236 as above described,thereby shifting valve 2I I to the position to have the discharge fromthe opposite end of the cylinder wheel into the work to reduce the sizethereof continues until the desired size is reached whereuponelectromagnetic means are energized for shifting the valve to a neutralposition and. stopping further movement of the wheel, thiselectromagnetic means and electrical interlock will be described indetail later.

The grinding wheel and carriage are now held stationary as far as anymovement of them relative to the bed is concerned to permit a sparkingout of the wheel and work and to permit the desired finish tobe had onthe work. The handle 2 I4 is then manually actuated in a clockwisedirection or toward the table 28 for shifting the valve 2I I to connectthe pressure line 2 I9 through the valve 2 with the conduit 285 fordirecting the hydraulic medium under pressure into the conduit 226 tothe right hand side of the piston I89 controlled. The movement of theI98 to retract the grinding wheel and carriage;

from the work and table. At this time the port 264 of conduit 265 isclosed off to prevent any fidw of the medium therethrough. The movementof the carriage and wheel toward the rear of the bed or away from theWork and table continues until the other side 286 of the shifter fork283 carried by the cylinder bracket I88 engages. with lock nuts 281carried by sleeve nut 288 for shifting same. This sleeve nut 288 isthreadedly carried by threaded portion 289 of a stop shaft 299 whichmoves with the nut 288. The shaft 290 is provided adjacent the threads289 with a splined portion 29I for rotating therewith a gear 292. Thegear 292 has a hub 293 forming the bearing for. rotation thereof whichis journaled in the bracket 213', similarly to the mounting of thetrigger or-trip shaft 215 and its gear 214. On the other side of thebracket 213 the shaft 290 has secured thereto for movement therewith afork 294 yieldably mounted on the shaft by a spring 295 so that the forkmay. give in the event of an obstruction or undue pressure being appliedthereto. The lower end of the fork 294 is connected with avalve rod 291extending from the rear of valve 2H for shifting the valve to a neutralposition and stopping the rearward movement of the carriage I83.

From this it will be understood that actuation of the handle 2 54 willinitiate a movement of. the grinding wheel carriage towardv the rear andthrough the interengagement of a shifter fork depending from thecarriage with the stop shaft the said stop shaft will be shifted forcorrespondingly actuating the reverse valve and stopping the carriage.

As was noted above the foregoing description deals with the shifting ofthe grinding wheel and carriage continuously toward the worksupportingtable and work at first at a rapid speed which isautomatically reduced to a slow or feeding rate to feed the wheel intothe work supported by the table. To actuate the grinding wheel towardthe table to feed same into the work piece at each end of the stroke ofthe reciprocable table the knob 228 is .adjusted to open the port 268andclose the port 261 of the valve casing 266. The grinding wheel andcarriage are then actuated toward the table at a rapid rate in the samemanner as described above by manually shifting the handle or lever 2I4about its pivot toward the operator to shift the valve 2 to the positionshown in Figure 21. This movement continues until, as above noted, thetrigger shaft engages the worm screw to dislodge the latch from beneaththe trigger when spring 251 will shift the valve 2| I to connect conduit226 and port 262 with port 264 conduit 265 thereby directing thehydraulic medium discharged from the cylinder on the other side of thepiston I90 into and through the conduit 265. At this time however, ,thehydraulic medium passes through valve casing 266 through port 268 to andthrough conduit 298 to a valve casing 299. The valve casing 299 enclosesa shiftable valve 300 having cannelures 39I and 302. As shown in Figure21, the hydraulic medium passes from the conduit 298 through port 303into the sleeve 299 which port 303 is connected by cannelure 302 with aport 304 from which conduit 305 extends. This conduit 305 terminates atone end of shuttle valve casing 306 which encloses a shuttle valve 301.The casing 306 on the other side of valve 381 communicates through port388 with a conduit 309 terv minating at its other end with port 3I0 invalve casing 299. This port M is connected through the cannelure 30Iwith a port 3 from which a conduit 3 I 2 extends for conveying thehydraulic medium back to the tank or sump 83. The grinding wheelcarriage and grinding wheel are fed into the work an amount equal to thedisplacement of the hydraulic medium between the end of the valve 301and the end of the casing 306. This distance is adjusted through theknob or control element 23I. In other words, the amount or volume ofhydraulic medium displacedfrom the casing 306 by the valve 301. removesthat amount of medium from the right hand side of piston I90 and permitsthe wheel to be fed into the work a distance corresponding to the saidvolume of oil displaced.

To reverse the valve 300 and consequently change the direction of flowof the medium through casing 299 and effect a shifting of the shuttlevalve 301, the said valve 300 is coupled in with the hydraulic motor 40so that upon each reversal of rotation of the motor the valve 300.

is reversely shifted through its casing. To this end a conduit 3I3connects the right hand side of the casing 299 with the lower side ofthe motor 49, as seen in Figure 21, while a similar conduit 3I4 connectsthe opposite or left hand side of the casing 299 with the upper side 40of the motor. Assuming now that if the pressure has been flowing fromthe directional "control or reverse valve 94 through the conduit 95 toactuate the motor 40 and a reversal of the valve takes place therebyintroducing the medium under pressure through conduit 96 to the upperside of the motorthe medium will at the same time flow through theconduit 3I 4 to the left hand'side of the valve 300 and shift same tothe right thereby connecting port 3I0 with 303 through the cannelure 30Iand connecting port 304 with port 3I5 through the cannelure 302. At thistime the hydraulic medium being discharged through conduit 298 will'pass through the ports 303 and 3I0 through to conduit 309 and port 308to the left hand side of shuttle valve 301 to shift same to the rightthereby discharging the medium ahead of the valve out through theconduit 305, ports 304 and-3I5 through conduit 3I6 to discharge conduit3I2 and at the same time permitting an infeed movement of the grindingwheel carriage I83 and grinding wheel 39. Again this intermittentfeeding of the grinding wheel into the work will continue to take placeat each end of the reciprocable stroke of the table until the work hasbeen reduced to the desired size at which time the electromagnetic meanscome into play for again shifting the valve 2| I to the neutral positionand stopping further movement of the wheel and carriage relative to thebed.

Associated with the tarry valve I34 and supported by the head I64 ofspool valve I52 is a switch arm 3 I1. for closing a switch 3I8 normallyheld open during the longitudinal movement of the table but closed whenthe said table is stopped.

From this it will be seen that each time the table stops at the end ofits recipro'cable movement before a reversal thereof is initiated theswitch 3 I8 is closed. This switch is wired in series with a switch thatcontrols the sizing of the work and which will now be described.

Mounted on the angularly extending guide ways 3l9 of the table is a baseplate 320 secured thereto by any desirable means,'such as a clamp 32I.The plate 320 has projecting upwardly therefroma lug 322 through whichan adjusting screw 323 extends. The threaded portion 324 of the screw isreceived in an internally threaded bore formed in pivot slide block 325.The slide block 325 has extending therefrom an ear 326 through which apivot 321 extends for pivotally securing a casing or housing 328thereto. Slidable through a bore 329 formed in the housing 328 is a;rack bar 330 being yieldably urged in one direction by a spring 33labuttingit on one end. The other end of the spring 33I engages anadjustable abutment 332 for providing the proper tension on the spring33L Meshing with the rack teeth of the bar 330 are the teeth of a gear333 rotatable with 7 a shaft 334 journaled in the side walls of thecasing 328. A pinion 335 also meshes with the gear 333 and is secured toa shaft 336 likewise journaled in the sides of the housing or casing 328but extending beyond one side thereof. A finger or sizing arm 331 issecured to the said shaft 336 on its protruding end and has a contactpoint 338 riding on the surface of the work piece 33.

Referring to'Figure 20, the spring 33I tends to actuate the rack bar 330toward the left thereby tending to rotate the gear 333 in a counterclockwise direction and through this gear to rotate the pinion 335,shaft 336 and gauging finger 331 in a clockwise direction. This holdsthe contact point 338 of the finger in engagement with the surface ofthe work piece which prevents further rotation of the parts justdescribed and holds the spring 33! undertension. As the surface of thework piece is reduced the arm 331 gradually completes its revolutionuntil the work piece has been reduced to the desired size at which timethe point 338 of the arm 331 is clear of the surface and the springexpands to actuate the rack bar the limit of its movement.

At this time the contact point 339 carried by an upstanding lug 340 onthe bar 330 engages the fixed contact 3 carried by the housing 328 tocomplete an electrical circuit. Thisswitch is wired in series with theswitch 3I8 so that if the switch M8 is closed at the time of completionof the work piece to size an electrical circuit is complete forenergizing a solenoid 342 mounted, see Figure 15, on the bracket 2 I1and connected with the upper end of arm 22!] for shifting the valve 2! Ito a neutral position and stopping further in-feed movement of thegrinding wheel and its supporting carriage.

After the work piece has been-reduced to size and it is desired toreplace the work piece on the table 28 the sizing device housing orcasing from the pivot 321 to engage a laterally extending lug 344 on therack bar 338 to retract the said rack bar and rotate the size arm 331 tothe downward position shown in Figure 19. As soon as the work piece hasbeen positioned the housing 328 is returned to the position shown inFigures 18 and 20 bringing the contact point of the arm 331 again intoengagement'with the surface of the grinding wheel.

As was noted above, the switch 3l8 is closed whenever the worksupporting table 28 is held in a stationary position or any movementthereof is interrupted so that the said switch is closed during theperformance of a plunge cut grindin'g operation since the reciprocatingtable is locked against movement at this time and the switch is likewiseclosed at the time the reciprocating movement of the table isinterrupt-edat each end of its stroke. Therefore, as soon as the workpiece has been reduced to size during the performance of a plunge cutgrinding operation the in-feed movement of the grinding wheel carriageand grinding wheel is immediately stopped. During the performance of acylindrical grinding operation utilizing the reciprocation of..the worksupporting table the switch M8 is normally open being only closed at theends of the movement of the table. Now, should the work piece be reducedto size after the re- 'versal of the table the switch 3i8 would be openwhile the switch within the casing 328 would be closed and remain closedso that upon reaching the end of the stroke of the table in the otherdirection the closing of the switch 3"! would then complete theelectrical circuit and actuate the solenoid 342 to stop the in-feedmovement of the carriage and wheel.

In the operation of the machine various Sims of work pieces are adaptedto be ground necessitating the adjustment of the grinding wheel and itscarriage relative to the bed. This adjustment, as noted above, isobtained through the cross feed hand wheel 203 for actuating the crossfeed screw I94. At the same time it is nec essary that the trigger shaft215 and stop shaft 290 be adjusted as a unit with the adjustment of thesaid grinding wheel and carriage so that the trip mechanism willfunction at the desired point to change the rapid movement of the saidcarriage to the desired slow feeding movement. This is accomplishedthrough the gears 214 and 292 'which mesh with the gear I96 on the screwI94 for simultaneously adjusting the nuts 219 and 283 relative to thescrew portions 218 and 289 respectively on the trigger and stop shafts.From this it will be seen that the zone of movement of the grindingwheel carriage under the influence of the hydraulic medium may bechanged without disturbing the particular setting of the trip mechanism.

What is claimed is:

1. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, agrinding wheel carriage carried by the bed and movable transverselythreof toward and from the work-supporting table, hydraulic means foreffecting the movement of the carriage including a reciprocating motor,an hydraulic medium for actuating the motor, means controlling the flowof the medium to actuate the carriage at a rapid rate, means controllingthe flow of the medium for actuating the carriage at a slow rate, meansoperable by the position of the carriage for automatically operativelyconnecting one of the above mentioned means with the medium toautomatically change the rate of movement of the carriage, andadditional means independent of the position of the carriage forautomatically shifting the valve to connect the medium with the otherrate control means for automatically changing the rate of movement ofthe carriage.

2., In a grinding machine the combination of a bed, a grinding wheelcarriage carried thereby and movable transversely thereof at a fast anda slow rate, an hydraulic reciprocating motor for effecting saidmovements, an hydraulic medium for actuating the motor, a. valvecontrolling the flow of the medium, manual means for initiating amovement of the carriage in reverse directions, automatic means forshifting the valve to change the rate of movement of the carriage fromfast to slow in one direction, automatic means for shifting the valve toa neutral position to stop the movement of the carriage in the said onedirection, and automatic means for shifting the valve to a neutralposition to stop the movement of the carriage in the reverse direction.

3. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, agrinding wheel carriage supported by the bed and movable transverselythereof toward and from the table, agrinding wheel supported by thecarriage for effecting a stock removalfrom the work piece supported bythe table, hydraulic means for effecting the said movement of thecarriage includ ing an hydraulic medium under pressure, a conduit forthe medium, a valve in the conduit controlling the flow of the mediumand having a neutral position to stop the said flow and an operativeposition to permit the said flow, manual means for shifting the valve toits operative po sition, electromagnetic means for shifting the valve toits neutral position, and means carried by the table controlling thesize of the work piece and electrically connected with theelectromagnetic means for shifting the valve to the neutral positionwhen the work piece has been reduced to the desired size.

4. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, agrinding wheel carriage supported by the bed and movable transverselythereof toward and'from the table, a grinding wheel carried by thecarriage for effecting a stock removal from the work piece supported bythe table, an hydraulic reciprocating motor for effecting the saidmovement .of the grinding wheel carriage, an hydraulic medium foractuating the motor, a valve controlling the flow of the medium having aneutral position for stopping the said flow of the medium, an operative'position to permit an unrestricted flow of the medium to actuate thecarriage at a rapid rate and an intermediate position for actuating thecarriage at a slow feeding rate, manual means for shifting the valve toits operative position, restrained yieldable means released by movementof the carriage for shifting the valve to its intermediate position, andelectro-magnetic means controlling the size of the work piece andoperable to shift the valve to its neutral position upon reducing thework piece to its desired size.

5. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, agrinding wheel carriage supported by the bed and movable transverselythereof toward and from the work supporting table, a grinding wheelsupported by the carriage for effecting a stock removal from the workpiece supported by the table, bydraulic means for efiecting the movementof the grinding wheel carriage comprising a cylinder carried by andmovable with the carriage, a fixed piston within the cylinder, anhydraulic medium for actuating the cylinder relative to the piston, avalve controlling the flow of the medium having a neutral position forstopping the flow of the medium, an open position permitting anunrestricted flow of the medium and a movement of the carriage at arapid rate, an intermediate position for restraining the flow of themedium and a movement of the carriage at a slow work feeding rate and areverse position permitting an unrestricted flow of the medium and arapid retraction of the carriage, and means automatically shiftable foradjusting the valve to its various positions including a pivotallymounted trigger having an operative connection with the valve, yieldingmeans for actuating the trigger about its pivot, a latch controlling themovement of the trigger, and a trigger shaft slidably carried by the bedadapted to be actuated by the carriage for disengaging mitting ashifting of the valve from an .open position to its intermediateposition under the influence of the yielding means.

' 6. In a grinding machine the combination of a bed, a work supportingtable carried thereby hydraulic medium,

the trigger and latch perand translatable longitudinally thereof, agrinding wheel carriage supported by the bed and movable transverselythereof toward and from the worksupporting table, a grinding wheelsupported by the carriage for eifecting a stock removal from the workpiece supported by the table, hydraulic means for effecting the movementof the grinding wheel carriage comprising a'cylinder carried by andmovable with the carriage, a fixed piston within the cylinder, an

hydraulic -medium for actuating the cylinder relative to the piston, avalve controlling the.flow I of the medium having a neutral position forstopping the flow of the medium, an open position permitting anunrestricted flow of the medium and a movement of the carriage at arapid rate, an intermediate position for restraining the flow of themedium and a movement of the carriage at a slow work feeding rate and areverse position permitting an unrestricted flow of the medium and arapid retraction of the carriage, means automatically shiftable foradjusting the valve'to its various positions including a pivotallymounted trigger having an operative connection with the valve,yieldingmeans for actuating the trigger about its pivot, a latchcontrolling the movement of the trigger, a trigger shaft slidably,

carried by the bed adapted to be actuated by the carriage fordisengaging the trigger and latch permitting a shifting of the valvefrom an open position toits intermediate position under the influence ofthe yieldingmeans, and a stop shaft slidably carried by the bedoperatively connected with the valveand adapted to be slidably actuatedby the carriage during its reversing movement for shifting the valvefrom a reverse position to its neutral position to stop the reversemovement of the carriage.

7. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, a toolsupporting carriage carried by the bed movable transversely thereoftoward and from the work supporting table, hydraulic means for effectinthe movement of said tool carriage including an a conduit for themedium, a valve in the cond thaving a neutral position, an openposition, an intermediate position and a reversing position, mechanicalmeans operable by the carriage for shifting the valve from an openposition to an intermediate position for changing the rate of movementof the tool carriage from a rapid rate. to a slow one, electromagneticmeans for shifting the valve to a neutral position when the work pieceon the work supporting table has been reduced to the desired size, andmechanical means operable by the carriage for shifting the valve from areverse position to a neutral one for stopping the reverse movement ofthe carriage.

8. In a grinding machine the combination of a bed, a work supportingtable carried thereby and translatable longitudinally thereof, a toolsupporting carriage carried by the bed movable transversely thereoftoward and from the work supporting table, hydraulic means for eifectinghydraulic medium, a conduit for the medium, a valve in the conduithaving 'a neutral position, an open position, an intermediate positionand a reversing position, mechanical means operable by the carriage forshifting the valve from an open position to an intermediate position forchanging the rate of movement of the tool carriage from the movement ofsaid tool carriage including an a rapid rate to a slow one,electromagnetic means for shifting the valve to a neutral position whenthe work piece on the work supporting table has been reduced to thedesired size, mechanical it means operable by the carriage for shiftingthe valve from a reverse position to a neutral one for stopping thereverse movement of the carriage, and means for varying the point atwhich the rapid movement of the carriage is changed to a. slow movementthereof.

l6 9. In a grinding machine the combination of a bed,'a work supportingtable carried thereby and translatable longitudinally thereof, means forautomatically reversing the translatory movement of the table, means foreifecting a slight tarry of the table at each reversal thereof, a toolcarriage carriedby the bed and movable transversely thereof toward andfrom the table to effect a stock removal from the work piece supportedby -the table, means for feeding the tool into the work piece at eachreversal of the table, an electric switch associated with the tarrymeans and adapted to be closed at each reversal of the table, a sizingdevice controlling the size of the work piec supported by the table, anelectric switch associated with the sizing device and adapted to beclosed when the work piece has been reduced to the desired size, saidswitch being wired in series with the switch associated with the tarrymeans, and means in series with the electrical switches for stoppingfurther feed of the tool carriage toward the work when the said switchesare both closed.

10. In a grinding machine the combination of a bed, a translatable worksupporting table carried thereby and movable longitudinally'thereof, arotating tool carriage carried by the bed and movable transverselythereof toward the work supporting table to feed the tool carriedthereby into the work, means for actuating the said tool 40 carriageincluding an hydraulic medium and a valve controlling the medium,electromagnetic means for actuating the valve to check the flow of themedium and stop further movement of the tool carriage, a housing carriedby the work supporting table, a work piece size controlling mechanismcarried by the housing including a rotatable shaft, yielding meanstending to rotate the shaft, a feeler arm on the shaft having a contactpoint in engagement with the surface of the work piece, the said contactbetween the arm and. the work piece restraining the yielding means fromrotating the shaft until the work piece has been reduced to the desiredsize, and

means closable by the yielding means when the 5 into the work, means foractuating the said tool carriage including an hydraulic medium and avalve controlling the medium, electromagnetic means for actuating thevalve to check the flow of the medium and stop further movement of thetool carriage, a housing carried by the work supporting table, a workpiece size controlling mechanism carried by the housing includinga-rotatable shaft, yielding means tending to rotate the shaft,

a feeler armbn the shaft having a contact point A in engagement with thesurface of the work piece, 1 the said contact between the arm and thework piece restraining the yielding means from rotating the shaft untilthe work piece has been reduced to the desired size, means closable bythe yielding means when the work piece has been reduced to the desiredsize for completing an electrical circuit and energizing theelectromagnetic means for actuating the valve to its stop position, andmeans pivotally securing the housing to the work supporting tablewhereby actuation of the housing about the pivotal mounting willposition the feeler arm for proper engagement with a new work piece.

12. In a grinding machine of the class described the combination with abed, of a grinding, wheel slide mounted thereon and movable transverselythereof, a work supporting table on the bed movable relative thereto,means for effecting the movement of said slide and table, means forreversing the movement of the table, means for determining the finalsize of the work being op-' erated upon, and an interlock between thetable reversing means and the size indicating means for stopping furthermovement of the grinding wheel carriage when the work is reduced to thedesired size.

13. In a grinding machine of the class described the combination with abed, of a grinding wheel slide mounted thereon and movable transverselythereof, a work supporting table on the bed mov-' able relative thereto,means for effecting the movement of said slide and table, means for re-'versing the movement of the table, means for determining the final sizeof the work being operated upon, and an interlock between the tablereversing means and the size indicating means for stopping furthermovement of the grinding wheel carriage when the work is reduced to thedesired size, said means comprising an electrical control mechanismincluding a pair of switches one associated with the table reversingmeans and the other with the work sizing means.

14. In a grinding machine of the class described the combination withabed, of a work supporting table mounted thereon for traversing movementrelative thereto, ,a grinding wheel carriage mounted on the bed formovement toward the work supporting table to effect a stock removal fromthe work piece thereon, hydraulic means for effecting the movement ofsaid table and grinding wheel carriage, each including a valve, meansfor shifting the table valve to reverse positions for effecting reversetranslations of the table, means for shifting the carriage valve to aneutral posi-. tion for stopping the said carriage, means operable bythe table for efl'ecting the movement of the table valve, a sizingdevice operable when the work reaches final size, and interlock means,associated with the sizing device and table valve actuating means toenergize the carriage valve shifting means and thereby shift said valveto its neutral position and stop. further movement of the carriage.

15. In a grinding machine of the class described the combination with abed, of a work supporting table mounted thereon for traversing movementrlativethereto, -a grinding wheel carriage mounted on the bed formovement toward the work supporting table to effect a,-stockremova1 fromthe work piece thereon, hydraulic means for effecting the movement ofsaidtable' and grinding wheel carriage, each including a valve,

means for shifting the table valve to reverse posh

